English

Dense clusters in hypergraphs

Combinatorics 2023-05-09 v2

Abstract

In this paper we solve the problem of finding in a given weighted hypergraph a subhypergraph with a maximum possible density. We introduce the notion of a support matrix and prove that the density of an optimal subhypergraph is equal to ATA|A^T A| for an optimal support matrix AA. Alternatively, the maximum density of a subhypergraph is equal to the solution of a minimax problem for column sums of support matrices. We introduce the spectral decomposition of a hypergraph and show that it is a significant refinement of the Dulmage-Mendelsohn decomposition. Our theoretical results yield an efficient algorithm for finding the maximum density subhypergraph and more generally, the spectral decomposition for a given weighted hypergraph.

Keywords

Cite

@article{arxiv.2304.02752,
  title  = {Dense clusters in hypergraphs},
  author = {Yuly Billig},
  journal= {arXiv preprint arXiv:2304.02752},
  year   = {2023}
}
R2 v1 2026-06-28T09:51:52.526Z